Overhead,rigid mast crane for pouring crucibles



Nov. 18, 1969 M. .1. DECHANTSREITER 3,478,907

OVERHEAD, RIGID MAST CRANE FOR POURING CRUCIBLES Filed Oct. 31, 1967 '7 Sheets-Sheet 1 ATTORNEY Iii Nov. 18, 1969 M. J. DECHANTSREITER 3, 7

OVERHEAD, RIGID MAST CRANE FOR POURING CRUCIBLES Filed Oct. 51, 1967 7 Sheets-Sheet;

mvnn'roz M.J. pECHRNTSEEITEe A1- TO 2 NSY Nov. 18, 1969 v M. .1. DECHANTSREITER 3,478,907

OVERHEAD, RIGID MAST CRANE FOR POURING CRUCIBLES ATTORNEY N 1969 M. J. DECHANTSREITER 3,478,907

OVERHEAD, RIGID MAST CRANE FOR POURING CRUCIBLES Filed Oct. 31, 1967 7 Sheets-Sheet muau 1-02 M. d. Danna/173351721? ATTORNEY Nov. 18, 1969 M. J. DECHANTSREITER OVERHEAD, RIGID MAST CRANE FOR POURING CRUCIBLES Filed Oct. 31, 196'? 7 SI'mets-Sheetv F AT TORNEY 1969 M. J. DECHANTSREITER 3,473,907

OVERHEAD, RIGID MAST CRANE FOR POURING CRUCIBLES M. J. pzcum/rjzz/ fee W 6?. 77%

- AT'I'QZNEY Nov. 18, 1969 M. J. DECHANTSREITER 3,4

OVERHEAD, RIGID MAST CRANE FOR POURING CRUCIBLES Filed Oct. 51. 196'? '7 Sheets-Sheet 7 I muau'roz. M. J. DECHHN7Z5ZEI7E2 ATT'OZNGY United States Patent US. Cl. 214-313 18 Claims ABSTRACT OF THE DISCLOSURE An overhead traveling crane especially for pouring molten metal into molds and the like, whereby the pouring spout lip of the crucible which holds the metal is the fulcrum or pivot point for the crucible during the pouring operation.

BACKGROUND OF THE INVENTION Power operated, overhead cranes, having telescoping masts, have been used for lifting crucibles, moving them from one location to another and tipping the crucible for pouring at the various stations. Cranes of this general type are shown in my US. Patents 3,286,853, issued Nov. 22, 1966, entitled Stacker Crane Power Lift Mechanism, or 3,247,974, issued Apr. 26, 1966, entitled Grab Stabilizer for Cranes.

The prior art, load carrying cranes used for pouring crucibles have had serious shrotcomings, particularly in their ability to pour accurately and without bodily maneuvering the entire crucible during the pour. It will be appreciated that when pouring an extremely heavy, large and hot crucible of molten metal, extreme care and accuracy are required to not only prevent spilling, but also to pour the precise .amount into the molds. Several molds are usually filled from one crucible load, and it has also been tedious and time consuming to tip the crucible the precise angular amount each time in order to pour the proper amount into the various molds.

SUMMARY OF THE INVENTION An overhead crane which efficiently picks up a pouring crucible and tips it about the pouring edge of the crucible spout as the pivot point so that it is only necessary to tip the crucible during the pour without the necessity of also bodily raising the mast and crucible, thereby providing rapid and very accurate pouring of the material without spilling or dribbling. The pouring edge of the spout can of the invention relate to the cradle construction for pick- .in up and supporting a conventional crucible while the pouring operation takes place; the safety means for locking the load carriage in the event of cable failure; and novel power operated cable means for tilting the crucible.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a front, elevational view of an overhead, dual mast crane embodying the present invention, certain parts being shown in section, broken away or removed for clarity in the drawing;

FIGURE 2 is a sectional view of the upper portion crane shown in FIGURE 1, the view being taken generally along line 2-2 in FIGURE 1, but on an enlarged scale, and certain parts being removed for the sake of clarity in the drawings;

FIGURE 3 is a sectional view, taken generally along line- 33 in FIGURE 1, but with certain parts removed for clarity in the drawing;

FIGURE 4 is a view generally similar to the lower portion of the device shown in FIGURE 3, but showing the crucible tipped to a pouring position;

FIGURE 5 is a sectional view along line 55 in FIG- URE 3, but on an enlarged scale;

FIGURE 6 is an enlarged, detail view of the safety yoke device as shown in the broken circle in FIGURE 3;

FIGURE 7 is an enlarged, detail view of the springloaded cam safety device as shown at the lower end of the mast in FIGURE 3, certain parts being shown as removed, broken away and in section for clarity;

FIGURE 7a is a detail, fragmentary view of the cam shown in FIGURE 7, but when moved to a mast locking position;

FIGURE 8 is a view taken along line 88 in FIG- URE 7;

FIGURE 9 is a perspective view of the cradle for supporting the crucible, the cradle being shown in the approximate position and from the same angle of view that it occupies in FIGURE 12;

FIGURE 10 is a view similar to the lower portion of FIGURE 3, but the view being a side elevational, rather than in section, of the lower portion of the mast and the cradle carried therein;

FIGURE 11 is a sectional view taken generally along line 11l1 in FIGURE 10;

FIGURE 12 is a perspective view of the lower portion of the mast and showing the crucible in the non-tipped position, the view being taken generally from the front or pouring side of the crane and at one side thereof;

FIGURE 13 is a view similar to that shown in FIG- URE 12, but showing the crucible in the uppermost, or tilt, pouring position;

FIGURE 14 (sheet number 2), is a perspective view of that portion of the crane shown generally in FIGURES 12 and 13, but the view is taken generally from the rear side of the crucible and shows the latter in an intermediate pouring position;

FIGURE 15 is a perspective, schematic view of the motor and brake; and the cam control box which are located at the rear and each side of the lower end of the crane, as shown in FIGURE 14;

FIGURE 16 is a vertical, sectional view, more or less schematic in nature, through one of the cam control boxes shown in FIGURES 14 and 15;

FIGURE 17 is a section view taken along line 1717 in FIGURE 16;

FIGURE 18 is an electrical wiring diagram used with the present invention.

EMBODIMENT A brief description of the general organization of the improved crane may be helpful before proceeding with a detailed description.

A means for supporting the rigid mast crane C has been shown as a large movable bridge B which travels along rails 1 and 2 located on the walls W, W1 or other structure. The crane includes a movable trolley T which runs on rails 9 and 10 fixed on the bridge. The main mast M depends downwardly from and may be rotatable on the trolley. Intermediate masts 36, 37 telescopingly slide over the rigid masts 30, 31, and a load carriage 76 is mounted on the intermediate masts and extends across between them. Power means are provided for raising and lowering the carriage. A cradle 90 is swingably mounted on the carriage and in turn has provision for picking up a Crane support Various ways of supporting the overhead traveling crane of the present invention may be employed, such as an overhead structural steel work or on the walls of buildings. For purposes of this disclosure, as shown in FIGURES l and 2, the walls W, W1 of a building have tracks 1 and 2, respectively, on which the pairs of wheels 3 and 4 ride to support the large traveling bridge B. This bridge includes the side members 5 and 6 which are rigidly connected together by the transverse, rectangular in cross section, beams 7 and 8. Rails 9 and 10 are fixed to the upper side of beam 7 and 8, respectively, and extend along the length thereof. Thus the bridge can move back and forth between the walls of a building and is usually of a considerable span.

CraneTrolley and main mast The dual mast crane C provided by the present invention includes a trolley T having two pairs of wheels 11 and 12 which are adapted to ride on appropriate rails, such as rails 9 and 10 on the overhead bridge B. The trolley is fabricated by welding steel girders together, such as girders 13 and 14 which form the sides of the trolley on which its wheels are mounted, and laterally extending I-beam girders 1-5 and 16 which are welded between the side girders 13 and 14. The central portion of the trolley has an opening 20 in which the upper end of the rigid mast M is rotatably mounted. More specifically, a large external gear ring 21 is fixed to the top of the trolley and around opening 20. The upper end of the mast M has a steel ring 22 rigidly fixed to its turret 23, and anti-friction bearings 24 are located in the opposed races of the ring 21 and ring 22 to thereby rotatably support the mast on the trolley for rotation about a vertical axis. A mast rotating, electric motor 25, through a gear reducer 26 is fixed by a plate 27 to the top of the mast M for rotation therewith. The motor drives a pinion 28 of the gear reducer, which pinion is in constant mesh with the ring gear of the mast. Rotation of the reversible motor causes the pinion to rotatably drive the mast around the ring gear 21.

Rigid mast The main mast M includes two rigid, laterally spaced apart, rectangular in cross section, masts 30 and 31 which are rigidly connected together at their upper ends by means of the cross beam 32 to which they are bolted by their flanges 33 (FIGURES 1 and 3). Masts 30, 31 and beam 32 are fabricated from steel sheets and beam 32 is welded to the underside of turret 23, with suitable gussets 34, as clearly shown in FIGURE 2.

Intermediate mast The main mast M also includes intermediate mast sections 36, 37, telescopingly mounted over masts 30, 31 respectively. The construction of intermediate mast sections 36 and 37 are similar, as are their connection to their respective masts 30, 31, and therefore only one will be described.

The intermediate mast section 36 is raised and lowered telescopingly over its mast 30' by a power connection in the form of a power driven threaded rod 40 (FIGURES l, 3 and 5) which extends downwardly in mast 30 and is driven by a centrally located electric motor 41 (FIG- URE 2) through a right angle gear drive 42 (FIGURES 1 and 2), shaft 43 and its worm 44, and a worm gear 45 (FIGURE 3) fixed to the top end of rod 40. A large nut member 47 (FIGURES 1, 3 and 5) is threaded on rod 40 for running up and down the rod as the latter rotates in one direction or another. The nut member 47 is latched to the inside of the intermediate mast section 30 by bracket 47a and. has a pair of pulleys 38 and 39 rotatably mounted thereon. As viewed in FIGURES 3 and 5, it will be noted that the inner side of mast 30 is open at 50 to permit the extending pulleys 38 and 39 to pass freely up and down in the opening 50.

Safety device A safety device is provided between mast 30 and intermediate mast 36, as shown best in FIGURES l, 3, 7, 8 and 14. This device includes a yoke 52 pivotally mounted at its center to the inside of mast 30. A cable 53 is fixed at one end to one end of the yoke, and the cable 53 is then trained over pulley 38 and its other end is then fixed on the outside of the load carriage 76 (to be described) by pin 55. Another cable 56 is fixed at one end to one end of the yoke 52, as trained over pulley 39, and its other end is then attached by pin 57 to a U-shaped bracket 58. Bracket 58 is vertically shiftable on a brace '59 welded to the load carriage 76. Pin 57 slides in and is guided by opposed slots 60 in the sides of brace 59. The lower end of bracket 58 has a pair of cables 61 and 62 fixed thereto which are trained around guides 63 and 64, respectively, and then are attached to one end of cranks 65 and 66, respectively, which in'turn are fixed on the outer ends of shafts 67, 68. Shafts 67 and 68 are oscillatingly mounted in the load carriage 76 and each have a cam 69, 70, respectively, rigidly fixed thereto. Each cam has a fiat surface 69a and 70m, which, when in the position shown in FIGURE 7, permits the load carriage 76 to slide over the intermediate mast 36; when the cams are in the position shown in FIGURE 7a, the masts are locked together. Springs 71, 72 bias the cams to the locked, FIGURE 70 position, and spring 73 biases the cams to the unlocked, FIGURE 7, position. Spring 73 is stronger than the combined strength of springs 71 and 72, thereby normally urging and holding the cams in the unlocked position.

The safety device also includes a normally closed microswitch 74 (FIGURE 6) engageable by one end of the yoke if cable 56 breaks or becomes slack, causing the cams to lock the carriage. Another microswitch 75 on mast 30 is engaged by the right end (as viewed in FIG- URE 6) of the yoke 52, when the latter raises, as when cable 53 breaks. Suitable fixed stops 77 and 77a are fixed on mast 30 and act to limit the swinging movement of the yoke 52 in one direction or the other when the safety device comes into operation.

The operation of the safety device is as follows. If either cable 53 or 56 becomes slack, either of the microswitches 74 or 75 will cut off the hoist motor. This causes bracket 58 (FIGURE 7) to drop, easing the bias of spring 73, permitting springs 71 and 72 to pull their cams to the locked position (FIGURE 7a) against mast 36. The weight of the carriage wedgingly locks the carriage against mast 36. If both cables go slack, a spring 77b moves to yoke 52 to contact micro-switch 75, also causes cut-off of the hoist motor.

After the broken cable has been repaired, and the carriage is to be lifted by the motor throguh cables 53 and 56, it is necessary to insure that the load of the carriage is not placed on the cam cables 61 and 62. This is prevented because the bracket 58 first raises to a point where its pin 57 reaches the upper end of slots 60 and bears against the brace 59. This takes the weight of the carriage and cables 61 and 62 are then-made taut by spring 73 which has been pulled upwardly, and thus cams 69 and 70 are snapped to the release position.

The load carriage 76, previously referred to, is vertically positioned, by the pulleys 3'8, 39 and cables 53 and 56, when the intermediate mast 36. is correspondingly moved by the power rod 40. The movement of thecarriage, however is double the rate of that of mast 36.,

Provision is made between the fixed mast 30 and inshafts 87a and 88a extending through the free ends Load carriage The load carriage 76 is generally U-shaped when viewed in plan (FIGURE 11) and has a rigid, central cross member 86 extending between and securing together its end sections which slide over the intermediate mast 36, 37 as previously described. Member 86 is of generally square cross section, is fabricated from heavy steel, and is fixed to the end sections of the carriage by flanges and bolts, as illustrated. Other ways of fabricating this heavy carriage may be employed, such as by making it as a single weldment.

The central, cross member 86 has a pair of generally downwardly extending double arms 87, 88 fixed to member 86, which are adapted to receive the cradle 90 (FIG- URE 9). The pockets of all these arms lie in a common axis 91. The cradle 90 can be tilted in the arms 87, 88 about the axis 91, as will appear. The member 86 also has arm means in the form of a pair of inner arms 89 which are adapted to receive the spout brackets of the crucible to be described.

The carriage 76 also has power means on it for tilting the cradle 90 (and the crucible 200 carried thereby) through ninety degrees. This power lift means includes electric motor drive means including a pair of electric motors 92, 93 and their attached gear reducers 94 and 95. The lift includes a power shaft 96 (FIGURE 14) 'having hoisting drums 97, 98 fixed thereto, 2 sets of pulleys 99, 100, another pair of pulley 101 and 102, and a cable 103. The electric motors 9.2, 93 have integral brakes of conventional design, and these motors may be referred to as pouring motors.

Thus the single cable and pulley arrangement form an equalizing device for the two pouring motors and the single shaft 96, thus distributing the load evenly and eliminating the need for an excessively large motor and torsional deflection of the shaft. The cradle is swung uniformly and positively with good accuracy and control.

As shown clearly in FIGURE 15, a shaft 110* also extends from one of thegear reducers 95 and drives a cam control device cc (FIGURES 16-18), more specifically a series of cams 111, 112, 113, and 114 which in turn actuate their respective micro switches 111a, 112a, 113a,

and 114a, as will appear.

Limit switches 115 and 115a are carried on a shaft 116 extending from the other gear reducer 94, and these switches set the upper and the lower stoplimits for the 'crucible. These switches could also be in the control box cc.

An operators cab 00 (FIGURE 1 and 11) is fixed to the carriage by pins 117 and bushings 118 (FIGURE 14), and this cab houses the controls for the circuit of FIGURE 18.

Cradle The cradle 90 includes a pair of laterally spaced, pick 'up arms 120, 121,'each having sheaves 122 and 123 the, trunnions 200a of the crucible 200 rest. A pair of cylindrical bearings 128, 129 at the front side of the cradle are adapted to be mounted between the double arms 87, 88, respectively, of the carriage, by means of of the arms and through the bearings 128, 129.

6 Crucible The crucible 200 may be of the conventional type having a pick up bail 207 (only shown fully in FIGURE 4) thatcan simply be locked rigidly in place when the crucible is used with the present invention. These crucibles include a spout 201 having a pouring lip 202.

Electrical circuit The electrical circuit includes manual control switches 210, 211; push buttons 212 for motors 92, 93; microswitches 111a, 112a, 113a, 114a, 115, and a, all previously referred to; a conventional control circuit transformer 214, overload relay controls 215, interlocks 216 for raise and lower, interlocks 217 on high and low speed, directional contactors 218, high and low speed contac tors 219, overloads 220, and relays RE for raise, lower, high speed and low speed.

Operation In operation of a foundry, many molds (not shown), may be located in a line and filled from a single crucible full of molten metal. The crucible is brought into the pouring area, on a cart (not shown) for example, and set on the floor. The conventional bail 207 of the crucible can then be locked in place because it is not needed for pouring when the present invention is used, or could be removed altogether.

When it is desired to pick up the crucible with the crane provided by the present invention, the spout 201 is first nested in the free ends of arms 89, which ends are open in an upwardly facing direction to form a pocket for the spout brackets 203 and 204 located one on each side of the spout. More particularly, these brackets include pins 203a and 204a which nest in the pockets of arms 89. After the spout bracket pins have been nested in arms '89,

the cradle 90 is rotated, by actuation of motors 92, 93 so that the cradle arms 121 and 120, and more specifically pick up pads 125 and 126', come into contact with the trunnions 200a of the crucible .200.

Continued operation of the pouring motors 92 and 93 causes tilting of the crucible to the amount determined by the micro switches to be hereinafter referred to.

For purposes of illustrating one example of how the invention can be utilized to successively pour four molds (not shown) from a single crucible, the crucible is tipped in four stages. These stages are predetermined, that is, the four pouring angles of the crucible are calculated to give four equal pouring amounts, it being necessary to return the crucible to the level position between pours. For example, say it has been determined that the maximum angle for each of the four pours is, respectively 22, 45, 67 and 90, as indicated by those designations in FIGURE 18 adjacent the appropriate microswitches for stopping the pouring motors at those angles of tilt of the crucible. When each of those angles is reached, the crucible can be backed off slightly by manual manipulation of the electrical control switches 210, 211 by the operator, to prevent dribble. The crane is then moved to the next mold when the next tilting operation by the motors 92, 93 takes place by the operator pushing one of the appropriate push-buttons 212, to bring in or close its adjacent relay contacts, and actuating the corresponding tilt limit micro-switch 111a, 112a 113a, 0 114a, thus shutting 01f the pouring motors. Iclaim: 1. An overhead traveling crane for a crucible having a pouring lip, said crane comprising a movable trolley, a rigid mast mounted on and extending downwardly from said trolley, said rigid mast including fixed mast means, and intermediate mast means telescopingly mounted on said fixed mast means for vertical movement in respect thereto; a load carriage mounted on said intermediate mast means for vertical movement relative thereto, a cradle swingably mounted on said carriage about an axis, pickup mens on said cradle for picking up and supporting said crucible with its pouring lip located at said axis, a power connection between said fixed mast means and said intermediate mast means for vertically positioning the latter, and a cable and sheve lifting connection between said intermediate mast means and said carriage for vertically moving the latter at a faster rate than that at which said intermediate mast means moves; and power lift means operatively connected between said carriage and cradle for swinging said cradle and crucible about said axis, thereby tilting said crucible about its pouring lip. 1

2. The crane set forth in claim 1 further characterized in that said carriage includes a pair of spaced apart arms, said cradle being mounted in said arms about said axis, said carriage also having inner arm means located between said pair of spaced apart arms, said inner arm means engageable with said crucible to hold said pour ing lip on said axis.

3. The crane as described in claim 1 further characterized in that said rigid mast includes a pair of spaced apart masts, an intermediate mast telescopingly slidable on each of said spaced apart masts, and said carriage is mounted on said intermediate masts and extends therebetween to connect them together.

4. The crane as defined in claim 1 further characterized in that said power lift means includes an electrical circuit, electric motor drive means in said circuit, a series of switches in said circuit which are selectively actuated by operation of said power lift means, said switches being connected to said motor drive means for stopping the latter and consequently the tilting of said crucible at predetermined angular positions of pour.

5. The crane set forth in claim 3 further characterized in that said carriage includes a pair of spaced apart arms, said cradle being mounted in said arms about said axis, said carriage also having inner arm means located between said pair of spaced apart arms, said inner and means engageable with said crucible to hold said pouring lip on said axis.

6. The crane set forth in claim 4 further characterized in that said carriage includes a pair of spaced apart arms, said cradle being mounted in said arms about said axis, said carriage also having inner arms means located between said pair of spaced apart arms, said inner arm means engageable with said crucible to hold said pouring lip on said axis.

7. An overhead traveling crane for a crucible having a pouring lip, said crane comprising a movable trolley, a rigid mast mounted on and extending downwardly from 'said trolley, a load carriage vertically movable on said rigid mast and including a pair of spaced apart arms, a cradle swingably mounted on said carriage and in said arms and about an axis, pick-up means on said cradle for picking up and supporting said crucible with its pouringlip located at said axis, said carriage also having inner arm means located between said pair of spaced apart arms, said inner arm means engagable with said crucible to hold said pouring lip on said axis, and power lift means operatively connected between said carriage andcradle for swinging said cradle and crucible about 'said axis, thereby tilting said crucible about its pouring 1i 8. The crane as described in claim 7 further characterized in that said rigid mast includes a pair of spaced apart masts, an intermediate mast telescopingly slidable on each of said spaced apart masts, and said carriage is mounted on said intermediate masts and extends therebetween to connect them together.

9. The crane as defined in claim 7 further characterized in that said power lift means includes an electrical circuit, electric motor drive means in said circuit, a series of switches in said circuit which are selectively actuated by operation of said power lift means, said switches being connected to said motor drive means for stopping the latter and consequently the tilting of said crucible at predetermined angular positions of pour.

10. An overhead traveling crane for a crucible having a pouring lip, said crane comprising a movable trolley, a rigid mast mounted on and extending downwardly from said trolley, a load carriage vertically movable on said rigid mast, a cradle swingably mounted on said carriage about an axis, pick-up means on said cradle for picking up and supporting said crucible with its pouring lip located at said axis, and power lift means operatively connected between said carriage and cradle for swinging said cradle and crucible about said axis, thereby tilting said crucible about its pouring lip; said power lift means includes an electrical circuit, electric motor drive means in said circuit, a series of switches in said circuit which are selectively actuated by operation of said power lift means, said switches being connected to said motor drive means for stopping the latter and consequently the tilting of said crucible at predetermined angular positions of pour,

11. An overhead traveling crane for a crucible having a pouring lip, said crane comprising a movable trolley, a rigid mast mounted on and extending downwardly from said trolley, and including a pair of spaced apart masts and an intermediate mast telescopingly slidable on each of said spaced apart masts; a load carriage vertically movable on said rigid mast and mounted on said intermediate masts and extending therebetween to connect them together; a cradle swingably mounted on said carriage about an axis, pick-up means on said cradle for picking up and supporting said crucible with its pouring lip located at said axis, and power lift means operatively connected between said carriage and cradle for swinging said cradle and crucible about said axis, thereby tilting said crucible about its pouring lip; said power lift means including an electrical circuit, electric motor drive means in said circuit, a series of switches in said circuit which are selectively actuated by operation of said power lift means, said switches being connected to said motor drive means for stopping the latter and consequently the tilting of said crucible at predetermined angular positions of pour.

12. The crane so defined in claim 11 further characterized in that said rigid mast includes fixed mast means, intermediate mast means telescopingly mounted on said fixed mast means for vertical movement in respect thereto, and said load carriage is mounted on said intermediate mast means for vertical movement relative thereto, a power connection between said fixed mast means and said intermediate mast means for vertically positioning the latter, and a cable and sheave lifting connection between said intermediate mast means and said carriage for vertically moving the latter at a faster rate than that at which said intermediate mast means moves.

13. The crane set forth in claim 11 further characterized in that said carriage includes a pair of spaced apart arms, said cradle being mounted in said arms about said axis, said carriage also having inner arm means located between said pair of spaced apart arms, said inner arm means engageable with said crucible to hold said pouring lip on said axis. I

14. The crane set forth in claim 12 further characterized in that said carriage includes a pair of spaced apart arms, said cradle being mounted in said arms about said axis, said carriage also having inner arm means located between said pair of spaced apart arms, said inner arm means engageable with said crucible to hold said pouring lip on said axis.

15. An overhead traveling crane for a pouring crucible having a pouring lip, said crane comprising, a movable trolley, a pair of spaced apart masts extending downwardly from said trolley, a load carriage movable vertically on said masts and including a pair of spaced apart arms extending therefrom, a cradle swingably mounted on said arms about an axis, said cradle having a pair of spaced apart pick-up pads adapted to liftingly support said crucible at opposite sides thereof, said load carriage also having arm means located between said pair of arms for supporting said pouring lip on said axis, and power lift means between said carriage and cradle for lifting and swinging the latter about said axis to there-by tilt said crucible about its pouring lip on said axis as said cradle is lifted.

16. A dual mast, overhead traveling crane for a pouring crucible which has a pouring lip extending from one side of said crucible, said crane comprising a movable trolley, a pair of rigid masts extending vertically down- Wardly in laterally spaced apart relationship, an intermediate mast telescopingly mounted over each of said rigid masts for vertical movement relative thereto, power means between each of said rigid masts and their corresponding intermediate mast for vertically positioning the latter together, a single carriage telescopingly mounted on both of said intermediate masts and having a cross. member extending therebetween, said cross member having a pair of generally downwardly extending and laterally spaced apart arms, a cradle swingably mounted in the lower ends of said arms for swinging through an arc about a single axis, a pair of laterally spaced pickup pads on said cradle for engaging opposite sides of said crucible and liftingly supporting said crucible, said cross member also having inner arm means located between said spaced arms for engaging and supporting said crucible with its pouring lip located on said axis regardless of the angular position of said crucible when it tiltingly swings with said cradle, and power means between said carriage and cradle for swinging the latter about said axis.

17. The crane as mentioned in claim 16 wherein said power means comprises, sheaves mounted on said carriagesand on said cradle at laterally spaced locations, a pair of electric motor drive means mounted on said carriage and drivingly connected to a single shaft, a pair of hoist drums fixed on said shaft, and a cable trained around said sheaves and adapted to be wound up on said drums.

18. The crane as described in claim 17 including an electrical circuit including said motor drive means, a series of micro-switches in said circuit and actuated by rotation of said shaft for stopping the motor drive means and consequently the tilt of said crucible at predetermined angular positions of pour.

References Cited r UNITED STATES PATENTS 

